JsonResult not returning (valid) json - Serializing going wrong?

问题

I try to make a simple call to a server-side method in ASP.NET MVC 4. I do this by making a jQuery call to a method. The method gets called and the properties are correct, but the response of this method is not correct. I try to serialize an .NET object using JSON.NET.

I can see I get the following response (using FireBug):

"{\"VisitorId\":\"11a0606b-5336-4fa7-b50f-3edf97d8301b\",\"PhoneToTransfer\":\"61793650\",\"PhoneToNotify\":\"\",\"EmailToNotify\":\"mcoroklo@gmail.com\",\"EmailToTransfer\":\"\",\"OrderState\":\"PaymentPending\",\"DestinationAddress\":\"1Ccypfi3rnXosUgY6p1sQVXFyddFvwLFEJ\",\"TransactionHash\":\"\",\"Value\":12.0,\"Confirmations\":-1,\"TransactionDate\":\"2013-01-09T22:36:33.7991116+01:00\"}"

This doesn't parse as correct JSON, and I have no idea why. Also, the "JSON" tab in Firebug says "There are no properties to show for this object".

I am pretty sure my content-type and dataType is correct on the call.

This is my code to make the JSON - using The JSON.NET library:

[HttpPost]
public JsonResult StartPurchase(string phoneReceiver, string emailNotify, string value)
{
    if (ModelState.IsValid)
    {
        BlockchainPayments block = new BlockchainPayments();
        var address = block.GetAddress(BtcContext.PurchaseSession);

        decimal val = 0;
        decimal.TryParse(value, out val);

        var ps = new PurchaseService();
        var purchase = ps.StartPurchase(BtcContext.PurchaseSession, phoneReceiver, emailNotify, address.destination, val);
        return Json(JsonConvert.SerializeObject(purchase));
    }
    return Json("Error");
}

This is the jQuery call:

$.ajax({
    type: "POST",
    url: url,
    data: dataToSend,
    dataType: "json",
    contentType: "application/json; charset=utf-8",
    success: function (data) {
        alert('Awesome destination succes');
    },
    error: function (date) {
        alert('An occurred while purchasing. Please try again later');
    }
});

Any idea why it's not returning valid JSON? And any ideas on how to solve it?

回答1:

It looks like you are double encoding it, just use one conversion method, e.g. return Json(purchase);

回答2:

return Json already serializes an object I believe. Looks like you're getting double serialization.

来源：https://stackoverflow.com/questions/14247131/jsonresult-not-returning-valid-json-serializing-going-wrong